GOFFSTOWN, N.H. — Tim Pawlenty’s puzzling decision at Monday’s debate to abandon a new line of attack on Mitt Romney’s health care record is prompting fresh doubts among members of his own party about his readiness to confront the GOP frontrunner.

One day after Pawlenty linked Romney’s Massachusetts health care plan with the federal health reform law as “Obamneycare” in a nationally televised interview, the former Minnesota governor retreated from the sharp critique at the first debate featuring Romney.

Pawlenty’s decision to back down — coming after his campaign promoted the original assault — was met with a mix of derision and bewilderment among veteran GOP strategists who are not committed to any of the candidates.

Few could recall another example of a candidate unveiling an attack in one high-profile forum, as Pawlenty did on “Fox News Sunday,” only to attempt to put the gun back in the holster in another such setting so soon afterward.

“Debates are competitions — they are alpha dog battles,” explained longtime GOP ad man Alex Castellanos. “To win one, you have to create what I call an ‘MOS,’ a moment of strength. Tim Pawlenty had a chance to get in the ring tonight with the heavyweight champion and create such a moment. He refused to enter the ring. It was like LeBron refusing to take the big shot [Sunday] night.”

“Pawlenty made an odd decision to back away from his health care attack on Romney which made him seem weak or at a minimum uncertain,” said Jim Dyke, a former top Republican National Committee official, adding: “Pawlenty probably should stick to prep and skip the bowling for the next debate.”

And Jason Miller, who worked on Rudy Giuliani’s 2008 campaign and is now a media consultant, said Pawlenty may have turned off the electorate he was hoping to impress.

“Republican primary voters are looking for a presidential candidate who’s going to take the fight directly to President Obama,” Miller said. “If you’re not comfortable following through on a criticism of one of your primary opponents in person, why should voters think you’ll be able to man up and follow through on a criticism of the president when you face him in the general election?”

The question here on the campus of Saint Anselm College from CNN moderator John King was straightforward: “Why ‘Obamneycare’?”

It also was completely predictable. By throwing his first serious punch at Romney on the eve of the debate, Pawlenty ensured that his health care attack would come up Monday night.

But when the question came, Pawlenty was caught off guard and offered a succession of halting answers.

First he tried to dodge, criticizing President Barack Obama’s approach to health care reform.

Pawlenty started backtracking, arguing that he had been asked about “similarities” between the Romney and Obama health care plans. “I just cited President Obama’s own words that he looked to Massachusetts as a blueprint,” Pawlenty said.

King’s follow-up was incredulous: “If it was Obamneycare on ‘Fox News Sunday,’ why is it not Obamneycare standing here, with the governor right there?”

That’s when Pawlenty just seemed to give up, abandoning his line of attack and reiterating: “Using the term ‘Obamneycare’ was a reflection of the president’s comments.”

After the debate, Pawlenty campaign manager Nick Ayers seemed to struggle to explain why his candidate abandoned the comparison.

“That assumes that we, like, program in answers on a candidate’s brain and say, ‘That’s exactly what you’re going to say,’” said Ayers, facing as many as a dozen reporters in the spin room. “Gov. Pawlenty’s his own guy. He said it himself on Fox on Sunday, and the way he chose to answer the question tonight is up to him, but he didn’t back off of it. He called it the blueprint of Obamacare and John wanted to hear him say ‘Obamneycare,’ so the governor then followed up and said ‘Obamneycare.’”

But neutral Republicans in attendance here said after the two-hour forum that they were baffled.

“It was not an, “I paid for this microphone,’ take-charge kind of moment,” said former New Hampshire GOP Chair Fergus Cullen, referring to Ronald Reagan’s famous “I am paying for this microphone” incident during a 1980 New Hampshire GOP debate.

“Pawlenty clearly decided he wasn’t going to engage. … Having used the loaded term just yesterday, not wanting to follow through was unexpected.”

Castellanos was even tougher: “A moment missed. A moment of strength that became a moment of weakness.”

The rapid reversal suggested dissension within the Pawlenty campaign about how and when to take on Romney. Such disagreements are standard fare within presidential campaigns. But rare is the moment when they play out in successive national TV appearances, illustrated by a candidate’s aggression one day and timidity the next.

It could be that Pawlenty himself went further than he and the campaign had originally planned Sunday — but his aides quickly emailed his “Obamneycare” soundbite to reporters and promoted it on Twitter after he made it.

The “Obamneycare” attack itself marked an abrupt shift for Pawlenty: Less than two weeks before, Pawlenty had told the Weekly Standard that he was determined not to be the first candidate to go negative.

Top Pawlenty officials declined to say why the former governor had changed his tune.

Instead, responding to a question about why the candidate declined to continue the offensive on health care, Ayers pointed a finger at the moderator.

“I recognize John King and CNN, for ratings purposes, wanted a spat to report on,” said the operative. “The fact of the matter is, Gov. Pawlenty continued to say tonight, that Romneycare was the blueprint for Obamacare.”

Just as worrisome for Pawlenty, Monday’s debate marked the emergence of Rep. Michele Bachmann (R-Minn.) as an articulate and unapologetic conservative standard bearer. Her continued rise could spell trouble for her fellow Minnesotan both at the Ames Straw Poll this Summer and at Iowa’s caucuses next winter.

The good news for Pawlenty is that the forum took place in June, not January of next year, when few eventual primary voters are paying close attention to the race. If Pawlenty does eventually go on the offensive against Romney, a halting start might ultimately be forgotten. Further, the exchange with King happened early in a two-hour debate and the Minnesotan found his footing in subsequent answers, offering strong answers on the economy and the role of faith in the country.

Yet every day that Romney is allowed to continue toward the primary unbruised by his GOP rivals is another day that he gets stronger as a front-runner. And throughout the 120 minutes here, he was able to deliver his economy-and-Obama message without having to duck any blows from his fellow candidates.

“It was a very friendly debate, to say the least, which helps Romney,” said longtime conservative PR man Greg Mueller, a top aide on Pat Buchanan’s 1996 presidential campaign. “No one took center stage and emerged as the main challenger to Romney. Bachmann got close in the beginning but did not take it far enough in my view. Consequently, Romney wins as he comes out unscathed and largely an unchallenged front-runner. Someone will emerge to challenge Romney from the right — it is for the taking. But it did not happen tonight. Gov. Pawlenty hit a lot of good base issues, and although he previewed the debate by coining ‘Obamneycare,’ he seemed to back off a bit on that challenger theme.”

In Chicago, Obama’s high command saw a bit of irony in the decision of a candidate who has been promoting himself as a truth-teller to pull his punches.

“Turns out, speaking ‘hard truths’ is harder than he thought,” quipped David Axelrod, the president’s top campaign strategist.